Since that original post, Amazon has come out with yet another service (still in limited beta) called Amazon SimpleDB. This is a simple but apparently powerful service to query structured data. Although I note some complaining from the database community about it not really being a database, that’s just a semantic issue. If they renamed it, the complaints would probably go away. I think I would describe SimpleDB as something like a content-addressable DHT.
BTW, I can’t help wondering if this new service is related to Amazon’s Dynamo. (This is total speculation on my part, BTW. Perhaps closer inspection will tell. Or maybe Amazon will, eventually…)